US2914307A

US2914307A - Carburetor construction

Info

Publication number: US2914307A
Application number: US537335A
Authority: US
Inventors: Olin J Eickmann
Original assignee: ACF Industries Inc
Current assignee: ACF Industries Inc
Priority date: 1955-09-29
Filing date: 1955-09-29
Publication date: 1959-11-24
Anticipated expiration: 1976-11-24

Description

Nov. 24, 1959 o. J. EICKMANN CARBURETOR consmucnon 3 Sheets-Sheet 1 Filed Sept. 29, 1955 FIG.I.

INVENTOR OLIN J. EICKMANN ATTORNEY Nov. 24, 1959 Filed Sept. 29, 1955 o. J. EICKMANN 2,914,307

CARBURETOR CONSTRUCTION 3 Sheets-Sheet 2 72 7/ 77 FIG.3.

mmvrox OLIN J. EICKMANN ATTORNEY.

Nov. 24, 1959 o. J. EICKMANN 2,914,307

CARBURETOR CONSTRUCTION Filed Sept. 29. 1955 3 Sheets-Sheet 3 INVENTOR. OLIN J. EICKMANN ATTORNEY United States Patent 2,914,307 CARBURETOR CONSTRUCTION I Olin J. Eickmaun, Normandy, Mo., assiguor, bymesne assignments, to ACE Industries, Incorporated, New York, N.Y., a corporation of New Jersey Application September 29, 1955, Serial No. 537,335

' 3 Claims. (Cl. 26134) This invention relates to carburetors and, more specifically, to a carburetor which features a novel arrangement of its elements, permitting a simplified construction, few parts, and a compact design. 1 Y

The actual carburetor described hereinafter is only four inches high, and is illustrated in full scale in the accompanying drawings, in which:

Fig. 1 is a top plan view with parts broken away and in section to reveal details of the construction.

Fig. 2 is an elevation in section taken on the line 22 of Fig. 1.

Fig. 3 is a side elevation in section taken on a center line of Fig. 1.

Fig. 4 is a side elevation of Fig. l with parts broken away to illustrate details of construction.

Fig. 5 is a top plan view with the cover removed.

Fuel bowl and float structure According to this invention, the carburetor, generally indicated as C is divided into two main sections. To facilitate manufacture, the main body of the carburetor 1 is a one-piece structure including the fuel bowls 2 and 3 and a mixture conduit 4. The usual throttle bodyis 3 by way of a nipple 9 having an integrally formed needle valve seat 10. Needle valve 11 controls the entrance of fuel through the nipple 9, and is urged against its seat by the buoyancy of

floats

13 and 14 shown in Figs. 1 and 5. Each float is supported on an arm which is similar in construction. Only one will be described, since a description of one will serve for both. For example, float 14 is. supported on an arm 16 (Figs. 1, 3 and 5) which has a vertical leg 17 apertured to receive the hinge pin 19 forming one bearing for hingedly supporting the float 14. The other bearing for the hinge, indicated as 20 in Fig. 3, is spaced by an offset portion of the arm 17 indicated as 21, which extends parallel with the hinge pin 19. Each offset 21 has an integrally formed finger 22, which fingers are located side by side in a position to engage the needle valve 11 as the floats rise.

This arrangement of parts provides for individual control of the fuel level by the

separate floats

13 and 14, so that fuel level may be accurately controlled, regardless of the tilt angle of the carburetor to either side.

Figs. 1 and 3 illustrate the mounting of the hinge pin 19. Opposite sides of the fuel bowl have opposed

slots

26 and 27 receiving the ends of the hinge pin 19. A bail 28 has opposite ends disposed within the

slots

26 and 27 and its intermediate portion engaged by the float bowl cover 6. This secures the pin 19 against vertical movev ice ment within the

slots

26 and 27, and holds thepin 19 stationary. 1

The fuel bowls 2 and 3, as best shown in Fig. 5,.have shallow extensions such as 31 and 32 located on opposite sides of the mixture conduit 4. In Fig. 4, the extension 31 has been shown in dotted lines. These shallow chamr'

bers

31 and 32 have their lower surface normally disposed at approximately the fuel level within the fuel bowls 2 and 3. When the. carburetor is tilted one way or the other about an axis transverse of the fuel bowls 2 and 3, the fuel will run in or out of the

shallow chambers

31 and 32. If the tilt angle is forward, or to the left, as in Figs. 1 and 5, the

shallow chambers

31 and 32 will receive enough fuel to maintain the fuel'level in the fuel bowl at a level below'the tip of the fuel nozzle. The carburetor will then continue to operate normally when tilted in this direction. If, on the other hand, the carburetor is tilted from the horizontal rearwardly, the shallow chambers are dry and do not add to or increase the' fuel level in the main fuel bowls 2 and 3.

Main nozzle system The main fuel system, including the main nozzle 37, is best shown in Figs. 1 and 2. Within the mixture conduit 4 is a main venturi 35 and a primary venturi 36.

Main fuel nozzle 37 extends into the primary ventun' 36 from a main supply passage 38. The upper end of supply passage 38 is vented to the mixture conduit at 39 through a small vent tube 40 extending below the entrance to: the main fuel nozzles 37. The lower endportion of passage 38 is offset to one side of throttle shaft to save space vertically. Fuel is supplied to the main fuel supply passage 38 through a pair of metering'orifices 42 and 43, both of which receive stepped metering rods. Metering rod 44 in orifice 42 is mechanically connected to be actuated by the throttle valve of the carburetor. The particularmechanism for operating rod 44 will be hereinafter described. I

Metering rod 46 has an end portion bent at right'angles received within a hole 47 in step-up piston 48. Cylinder 49 containing the piston 48 is connected to the mixture conduit 4 posterior of the throttle by way of-passages 50 extending to a port (not shown) positioned below the throttle. A spring 53 within the cylinder 49 urges the piston 48 to its uppermost position, which is limited by a diaphragm or gasket 54 secured beneath the removable dust cap 55.

The parts of the main metering structureare so arranged that opening of the throttle moves the rod 44 downwardly so as to increase the flow through the metering orifice 42. Metering orifice 43 acts as an economizer and as a mixture step-up at higher manifold pressures when spring 53 is permitted to expand by decreasing suction on the piston 48. Bleed tube 40 projects into the main supply passage 38 to a point below the entrance of the main fuel nozzle 37, so that, during action of the main fuel system, the solid fuel flowing to the main nozzle will be broken into an emulsion by the addition ofa jet of air from the nozzle bleed tube 40.

Idle fuel system The system for supplying fuel to the engine within the low range of engine speed is best shown in Figs. 2 and 4. In the idle system is a diagonally extending passage 59 containing an idle tube 60 having a flange 61 seated as at 62 at the upper end of the passage 59. In the bowl cover is an offset passage 63 for connecting the passage 59 to vertical passage 64 containing metering orifice. 65. As shown. in Figs. 4 and 5, passages 59 and 63extend aroundthe mixture conduit 4so that the idlesystem and main nozzle supply system are arranged side by side.

Po rt 66 in the side of passage 64 opens into the mixture 3 conduit 4 slightly anterior of the throttle valve. A second port 67, controlled by a metering screw 68, connects by way of passage 69 to a second port 70 posterior of the throttle valve; r

Accelerating pump Located between and within the fuel bowls 2 and 3 is -a cylinder 71, best shown'in Fig. 3. A piston 72 in the cylinder 71 has a mounting sten173 extending through the float bowl cover 6. At its upper end, the stem 73 has a flat 74, which terminates in abrupt, spaced shoulders.

Connected with the throttle shaft 75 is a short lever 76 having a pin .77 at its outer end. A link .78 having a slotted lower end receiving the pin 77 extends through aslot 79 (Fig. formed in a raised boss within the .fuel .bowls 2 and.3,, and also through a suitable slot in .the floatbowlcover 6 under dust cap;55. .The connectionbetween the throttleshaft 75 andlink .78 is such that opening movement of the throttle 80 causes downward movement of the link 78.

As best shown in Fig. 1, the upper end of link 78 has a pair of

arms

82 and 83, the latter of which isconnected to the metering rod 44 by spring clip 84. Opposite arm 82 is received between the spaced shoulders of the machined flat 74 on the pump stem 73. Sur- ,rounding the stem 73 is a compression spring :86 constantly urging the-piston 72 downwardly.

The structure above described will maintain the piston 72 in its upper position, compressing the spring 86 when the throttle valve 80 is closed. Opening movement of the throttle 80 permits expansion of the spring 86, forcing thepiston 72 downwardly. Because of the lost motion connection'between the arm 82 and the stem 73, the rate of descentof the piston is independent of throttle movement.

On downward movement, the fuel trapped below the 'piston 72 is forced outwardly through a discharge passage 90 controlled by a check valve 92. As shown in Fig. 3, the passage 90 opens at. the top of the boss which contains the slot 79 for the throttle lever 78. When the float bowl cover 29 is in place, this passageis closed, as shown in Fig. 3., Check valve 92 is maintained in position by a U-spring 94 in the top of the passage 90.

Fuel passing the check valve is discharged through a nozzle 96 which is completely within the float bowl as shown in Figs. ,3 and .5. A passage 97 connecting between the float bowl and the mixture condnit'4 is located in direct alignment with the nozzle 96, so that fuel discharged under substantial pressure will pass .through the passage '97 into the mixture conduit 4. On the other hand, any leakage from the nozzle 96 will simply return to the float bowl. The location of the discharge nozzle 96 has the added advantage that'it is exposed to substantially atmospheric pressure, and not the action of suction within the mixture conduit 4. Any suction which exists at the discharge end of the passage 97 merely creates a circulation within the mixture conduit, since the passage has an atmospheric bleed 95, as shown in Fig. 3.

Certain structures have been described herein which will fulfill all the objects of the present invention, but it is contemplated that other modifications will be obvious to those skilled in the art which come within the scope of the invetnion as defined. bythe appended claims.

I cl im:

1. A carburetor for an internal combustion engine having a mixture conduit therein, comprisinga fuel reservoir in said carburetor, a rotatable throttle shaft journaled in the walls of said carburetor transverse said mixture conduit, a throttle valve mounted on said throttle shaft, yentur'i means in said mixture conduit anterior 'to said throttle valve, a main fuel supply systemjn said carburetor for discharging fuel from saidfuel reservoirto said mixture conduit adjacent said venturi means in response to engine demands, an idle fuel supply system in said carburetor for discharging fuel from said fuel reservoir to said mixture conduit anterior and posterior of said throttle valve when said throttle valve is substantially closed, a metering rod in said carburetor for regulating the amount of fuel passing from said fuel reservoir to said main fuel supply system, an accelerating pump having a piston mounted in a cylinder in said carburetor for reciprocal movement therein, means for charging said cylinder with fuel from said fuel reservoir upon movement of said piston in one direction, means for discharging fuel from said cylinderinto said mixing conduit'upon movement of said piston in the other direction, a piston rod aflixed to said piston, a biasingspring circumferentially disposed about said piston rod urging said piston in said discharging direction, stops formed by a recess in said piston rod in the direction of said reciprocal motion, an actuating member aflixed at one end to said throttle shaft and mounted in said :carburetor forirecip- .rocal movement along an axis generally parallel to the axis of reciprocal movement of said piston rod andsaid metering rod, a transverse arm aflixed to the other end of said actuating member, saidtransverse arm having one end thereof operatively connected to said metering .rod and the other end thereof havinga portion smaller than the spacing between said stops and received between said stops of saidpiston-rod, whereby said actuatingmember and said metering rod and saidpiston rod are operatively connected together.

2. A carburetor for an internal .combustion engine having a mixture conduit therein, comprising a fuel reservoir in said carburetor, a rotatable throttle shaft journaled in the walls of said carburetor transverse said mixture conduit, .a throttle valve mounted .on said throttle shaft, venturi means in said mixture conduit anterior to said throttle valve, a main fuel supply system in said carburetor for discharging fuel from said fuel resei oir to said mixture conduit adjacent said venturi means in response to engine. demands, an idle fuel supply system in said carburetor for discharging fuel from said fuel reservoir to said mixture conduit anterior and posterior of said throttle valve when said throttle valve is substantially closed, a metering rod in said carburetor for regailating the amount of fuel passing from said fuel reservoir to said main fuel supply system, an accelerating pump having a piston mounted in a cylinder in said carburetor for reciprocal movement'therein, means for charging said cylinder with fuel from said fuelreservoir upon movement of said piston in one direction, means for discharging fuel from said eylinderinto said mixing conduit upon movement of said piston in-the other direction, a piston rod affixed to said piston, 'abiasing spring circumferentially disposed about said piston rod urging said piston in said discharging direction, stops formed by a recess in said piston rod in the direction of said reciprocal motion, an actuating member affixed at one end to said throttle shaft and mounted 'in -said carburetor for reciprocal movement along an axis-generally parallel to the axis of reciprocal movement of said piston rod and said metering rod,.a transverse arm integral with the other end of saidactuating member, said transverse arm having one end thereof operatively connected to said metering rod and the other end thereof received between said stops of said piston rod, whereby said actuating member operatively urges said piston rod ina direction to charge said cylinder with fuel.

3. A carburetor for 'an internal combustion engine having a mixture conduit therein, comprising a fuel .reservoir in said carburetor, a rotatable throttle shaft journaled in'the walls of saidcarburetor transverse said mi ture conduit, a throttle valve mounted on said throttle shaft, venturi means in said mixture conduit anterior to said throttle valve, a main fuel supply system in said carburetor for discharging fuel from said fuel reservoir to said mixture conduit adjacent said venturi means in response to engine demands, an idle fuel supply system in said carburetor for discharging fuel from said fuel reservoir to said mixture conduit anterior and posterior of said throttle valve when said throttle valve is substan- .tially closed, a metering rod in said carburetor for regulating the amount of fuel passing from said fuel reservoir to said main fuel supply system, an accelerating pump having a piston mounted in a cylinder in said carburetor for reciprocal movement therein, means for charging said cylinder with fuel from said fuel reservoir upon movement of said piston in one direction, means for discharging fuel from said cylinder into said mixing conduit upon movement of said piston in the other direction, a piston rod aflixed to said piston, a biasing spring circumferentially disposed about said piston rod urging said piston in said discharging direction, stops formed by a recess in said piston rod in the direction of said reciprocal motion, an actuating member aifixed at one end to said throttle shaft and mounted in said carburetor for reciprocal movement along an axis generally parallel to the axis of reciprocal movement of said piston rod and said metering rod, a transverse arm integral with the other end of said actuating member, a fastener operatively 6 connecting said transverse arm at one end thereof to said metering rod, and the other end of said transverse arm received between said stops of said piston rod, whereby said actuating member operatively urges said piston rod in a direction to charge said cylinder with fuel.

References Cited in the file of this patent UNITED STATES PATENTS 1,933,360 Barbarou Oct. 31, 1933 2,186,480 Ensign Jan. 9, 1940 2,212,926 Wirth Aug. 27, 1940 2,274,467 Ball Feb. 24, 1942 2,312,819 Heftler Mar. 2, 1943 2,493,804 Carlson Jan. 10, 1950 r 2,625,382 Boyce Jan. 13, 1953 2,633,085 Hieger Mar. 31, 1953 2,635,625 Moseley et al. Apr. 21, 1953 2,635,863 Olson Apr. 21, 1953 2,655,359 Winkler Oct. 13, 1953 2,658,733 Boller Nov. 10, 1953 2,757,914 Ball Aug. 7. 1956